There is a recent tendency to multi-function vehicles possessing not only such basic functions as running, turning and stopping but also a navigation function which utilizes position measurement by a Global Positioning System (GPS) and a vehicle-to-vehicle communication function. This tendency is becoming more and more conspicuous in quick tempo. Besides, importance is being attached to the design in both interior and exterior of a vehicle. Keeping steps with such a tendency, there also is a tendency that various parts and parts assemblies for fulfilling various functions are attached to the inside of an instrument panel. For example, an antenna assembly for receiving radio waves from road machines such as a GPS and an Electronic Toll Collection (ETC) system is also attached to the inside of an instrument panel. As shown in FIG. 9, the antenna assembly is attached to a central position of a vehicle front portion in order to keep a good radio wave receiving condition. In FIG. 10, a central part in the transverse direction of a vehicle is cut in the longitudinal direction of the vehicle and the result is shown in terms of a schematic sectional view. An approximate position of an antenna assembly attached to the inside of the instrument panel is shown in the same figure.
In connection with a configuration for mounting the antenna assembly to the instrument panel of a vehicle, such a technique as shown in FIGS. 11 to 13 is disclosed in Japanese patent literature JP-2004-276770A. FIG. 11 is a sectional view wherein the antenna assembly and the vicinity thereof shown in FIG. 10 are enlarged and the appearance of the antenna assembly as attached to the instrument panel is shown in more detail. In the illustrated configuration, an antenna body 31, together with a bracket 13, constitutes an antenna assembly 30 (see also FIGS. 12A and 12B). Further, the antenna assembly 30 is fixed to an instrument panel 10 together with a bracket 12 which is clamped and fixed with screws 14 to a mounting boss 11 of the instrument panel 10.
In order to effect such an assembly as shown in FIG. 11, first, as a preliminary operation, the antenna body 31 is attached to the bracket 13 to complete the antenna assembly 30, as shown in FIGS. 12A and 12B. Thereafter, the antenna assembly 30 is attached to the bracket 12 and lastly the bracket 12 is secured with screws 14 to the mounting boss 11 of the instrument panel 10.
In the above configuration, as shown in FIGS. 13A and 13B, the mounting of the antenna assembly 30 to the bracket 12 is performed by fitting engagement between a fitting portion 15 which is formed on the bracket 12 so as to project upward and a fitting hole 16 formed in the bracket 13. The mounting in question is easy and does not require such parts as screws. Thus, the configuration is simplified. A worker for the mounting is merely required to slide the bracket 13 in A′ direction until fitting of the fitting portion 15 into the fitting hole 16 along with a guide portion 17 of the bracket 12.
There sometimes is a case where the check of performance and replacement of antenna is required after mounting the antenna assembly 30 to the bracket 12 and fixing it to the instrument panel 10. In this case, by disengaging the fitting portion 15 and the fitting hole 16 from each other and sliding the antenna assembly in the direction of A, the antenna assembly 30 can be removed easily from the instrument panel 10 (the bracket 12 integral with the instrument panel 10).
At present, since there are a wide variety of vehicle models, the shape of an instrument panel and the layout of parts attached to the instrument panel differ each vehicle model. It is an essential premise that an antenna assembly should be mounted without interference with other parts attached to the instrument panel.
However, in the mounting structure referred to above in connection with the description of the background, in order to avoid the above-mentioned interference, it is necessary that the bracket 12 for fixing the antenna assembly 30 to the instrument panel 10 be designed and fabricated correspondingly to the instrument panel shape and parts layout which differ for each vehicle model. Besides, the bracket 12 is absolutely necessary. Thus, there is a problem of an increase in the number of parts. Moreover, the screws 14 are needed for securing the bracket 12 to the instrument panel. Also in this point the problem of an increase in the number of parts is encountered.
Further, when mounting the bracket 12 to the instrument panel 10, the instrument panel 10 before mounting thereof to the vehicle is turned inside out and a mounting work is performed, with a back side 10-1 up, to tighten the screws 14. However, the working space is limited because many other parts and parts assemblies are installed in the interior of the instrument panel 10. Thus, the screwing work is not easy. If the worker should drop any of the screws 14 to the interior of the instrument panel 10 by mistake during the work, it is difficult to recover the dropped screw.